5. Brocade-Foundry: $2.6 billion

Were still waiting for the i's to be dotted and t's to be crossed on this deal, initially . The value of the deal was downgraded from $3 billion to $2.6 billion , Brocade secured a loan in October to , and in November Foundry let pass a deadline by which it could have . The combination of Brocade and Foundry is seen as a direct effort to combat Cisco with a broader data center product collection, exploiting Brocade's strength in and Foundry's powerful routers.

6. Microsoft-Fast Search and Transfer (FAST): $1.2 billion

, suggesting that enterprise search has hit a tipping point, announced plans in January to gobble up this . Microsoft's efforts to play catch-up with also included a mid-summer buyout of search engine company Powerset for an . Unfortunately for Microsoft, the FAST deal hasn't been entirely smooth, as the Oslo-based outfit was charged with in November by Norwegian police. 

7. Sun-MySQL: $1 billion